<p>The connecting structure between the switching modules of a digital switching network contains redundant transmission links, the operating state of which is changed by means of a reconfiguration in the event of a failure of the active transmission links and which thus replace the failed active transmission links. These redundant transmission links can only be checked by routine reconfiguration. The invention ensures that the redundant transmission links can also be monitored for intactness in their redundant operating state. <IMAGE></p>
